Improvement in reversible safety-pinion for watches



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BENJAMIN BACON, OF MORRISON, ILLINOIS, ASSICNOR,BY IWIESNE ASSIGN MENTS,TO NATIONAL WATCH COMPANY.

Letters Patent N 96,865, dated November 16, 1869.

IMPROVEMENT IN REVERSIBLE SAPETY-PINION FOR WATCHES.

The Schedule referred to in these Letters Patent and making part of thesame.

To all persons to whom these presents muy come:

Be it known that I, BENJAMIN BACON, of Morrison, in the county oflVhtesidcs, and State of Illinois, have invented a new and usefulImprovement in \Vatehes; and I do hereby declare the same to be fullydescribed in the following specitication, and represented in theaccompanying drawings, of whiclr- Figure 1 is a top view, and

Figure 2, a longitudinal section of a pinion, with its gear and arborprovided with my invention, the purpose of which is to enable the pinionto revolve backward freely on its arbor, when breakage of the mainspringof the barrel of a watch may take place, the object being to preventinjury to the train, which would otherwise be likely to happen.

In the drawings- A denotesthe pinion, which engages with the gear ofthebarrel in which the main-spring of the works of a watch is situated. v

B is the arbor of such pinion, and the gear C, to be revolved by suchpinion.

The pinion is to revolve freely on the arbor, but is to be coupled witha nut, D, screwed on the arbor, as shown at s, and against the pinion,the coupling being a Studer pin, a, extended from the pinion into acorresponding notch, b, made in the nut. A ratchet and pawl may besubstituted for the pin and notch, or there nia-y be other modes ofcoupling the pinion and nut, when they are in separate pieces.

Then the pinion is turned in one direction on the shaft, it will turnthe nut so as to screw ittoward the pinion, and force ythe latteragainst the gear, so as to cause the pressure and friction against thegear to cause the said gear to revolve with the pinion; but when themain-spring nia-y break, and what is called back-action follows, thepinion will be free to rcvolve on the shaft, and will revolve andunscrew the nut, and will impart no rotary motion to the gear or ardor,thus overcomingr all danger of injury to the train by reason ofthereaction ofthe spring, resulting from breakage of it.

This Inode of applying the pinion is much better than by securing thepinion on the shaft, or by holding the pinion by friction alone, both ofwhich modes not have to he screwed tight at all, but the power of l themain-spring screws it up when the power is applied, or the watch woundnp. In this case it will be seen that the pinion is perfectly loose, andthe least baclbaction willl unscrew the nut and pinion, and the latterwill be perfect-ly loose, but still they are both in their place againwhen the watch is wound up.

This 'is notso with thenut alone, for when'the nut is loosened by theback-action, the pinion remains loose,

and the watch has to be taken in pieces,and the nut screwed up again.

Should a person or a watchmaker be not perfectly well posted as to howtight the nut should be screwed up, he may screw it so tight that theback-action will not turn the. nut, in which case the nut is of no availwhateverthc pinion then being liable to break by the back-y notion justas much as if there were no loose pinion.

The pinion might as well he fastened tothe arbor, as to'ha-ve a nut thatis screwed so tight'that it will not turn. With my improvement, thepinion will always turn when there is back-action. l

Again, if, under ordinary circumstances, thcnut is not screwed tightenough, the pinion will turnaround when the watch is heilig wound up,and will let the spring tl y hack or run down. This is not so with myinvention, for the pinion cannot turn without the nut. I claim in the'train of a watch, the combination and arrangement ofthe separate nut I),and the coupling, substantially as described, with the pinion A, and thearbor B, its screw and gea-r C, the whole being to opcrate as specified.

BENJAMIN BACON.

XX-iitiiesscs: .i

B. H. Bacon,

WILLIAM LANE.

